Encore timeline movie tempo problem

Hi

Im pretty new to this, but I can't find anything about this problem, so forgive me if this is a newbie mistake.

When I import a video into a timeline in Encore, be it an mpg or an m2v file, the timeline somehow shortens the movie file. The timeline stretches out to the correct amount of time, but the video (1;32;19;12) fills out the last 15 minuttes or so with nothing but black screen. So now my video suddenly is only 1;14;35;00 long. I appears that everything from the movie is there, but apparently just speed up quite a bit. When I try to burn a disc with the project the films length is correct though, but video-thumbnails I try to make follow the wrong timed movie file, so the images in them dont match where you go in the film when you click them.

Does this ing any bells with anyone? Any solutions perhaps?